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Is Multi-Modal Level of Service a Waste of Time?

6/23/2016

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We recently received a Request for Proposal for a corridor project that asked us to include an analysis of Multi-Modal Level of Service for a number of concepts. I don't think that's the right approach. Here's why...

Automobiles

Level of Service or LOS for short, has long been the universal easy to understand measure of intersection performance for automobiles. It effectively assigns a rank of A to F to the level of vehicle delay on approach to an intersection and is used with some other metrics to show if an intersection will operate at an acceptable level. With regard to Level of Service, LOS A to D reflects acceptable delays, LOS E to F reflect unacceptable delays. LOS E or F might look something like this...
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A clearly popular road being well used. In the traffic engineering world, that is a very bad thing, congestion, traffic jams, gridlock are some popular descriptions. Alternatively, LOS A might look like this...
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This is seen as a good thing in our car centric world, the road network will be operating with lots of spare capacity meaning nobody is delayed. We can debate the logic of potentially overbuilding another day, onto other modes...

Pedestrians

Applying similar principles to pedestrians (and cyclists) is counter productive. The goal of any urban realm improvements should be to pack the space with people. Here is a busy street, its crowded, people walk slowly, don't have much personal space, and it probably has a poor LOS.
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But it looks way more appealing than this street, much less crowded, much more space per person, but it felt kinda lonely, and almost unsafe walking down it. It probably has a very good pedestrian LOS. 
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Cyclists

Its similar for cyclists, here is a protected bike lane, the type that encourages use and a consistent stream of cyclists, there may be mild congestion at intersections but its a pleasant experience to use it and an example of good design. LOS is almost irrelevant, safety is the important factor.
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Below is a road with Sharrows, it doesn't feel as safe, therefore cyclists tend to avoid it, LOS may be good or better than the above facility, but again, safety is the most critical factor when designing such a facility.
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So...

Here's the thing, pedestrian and bicycle facilities are much more personal modes of travel. The things that make them work are more touchy feely than what pure numbers can tell us. We know what kind of facilities people like to walk and bike on, ones that make them feel safe.

Furthermore, when developing concepts for a corridor improvement study, if it is to be a truly multi-modal corridor, one that encourages trips by other modes and doesn't just paint bicycles in the traffic lanes, best practice has shown the kind of infrastructure that works. The width of such facilities is unlikely to change too much.

The level of demand for such facilities will not be constant. It will be subject to the type of facility provided in each option (and the wider connectivity provided). Predicting that demand is a very difficult thing to do, thus calculating an accurate LOS is also very difficult, if not meaningless. If its crowded... yeah! We created somewhere people want to be!

We can't just take a notional number of say 50 or 200 cyclists/hour and apply that to a wide curb lane with Sharrows and a separated bike lane with planters to protect them, one is going to discourage trips and one is going to encourage them.

When it comes to designing for pedestrians and cyclists, safety is paramount, Level of Service not so much!
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